Antiscreening channels for ion-ion collisional excitations in lense plasmas

Plasma-screening effects are investigated on antiscreening channels for excitation of a one-electron target by a one-electron projectile in dense plasmas. The interaction Hamiltonian in dense plasmas is obtained by an appropriate form of the nonspherical Debye-Huckel potentials. Semiclassical straight-line trajectory method is applied to the ion projectile path in order to visualize the antiscreening transition probability in dense plasmas as a function of the impact parameter and the collision energy. The plasma screening effects reduce the transition probabilities, especially, in the dipole-dipole transition. The maximum position of the transition probability is receding from the target nucleus with increasing projectile energy for the dipole-dipole and dipole-quadrupole excitations. However, in the quadrupole-quadrupole excitation, the maximum position is getting closer to the target nucleus with increasing projectile energy. The quadrupole transitions (dipole-quadrupole and quadrupole-quadrupole) show the second maximum which is due to the double peaks of the 2s radial distribution function. (C) 1997 American Institute of Physics.